The means to non-intrusively detect and measure electric current on conductive cables through induction techniques is well known and described in the prior art. For example, see U.S. Pat. No. 4,804,917 "Current Detection Device Having an Extended Frequency Range of Response," which discloses a device designed to detect current in a broad range of frequencies. The '917 device detects a drop in voltage on a conductive substrate to detect current over a wide frequency range, with the invention targeted to detecting the presence of electronic noise on coaxial cables. Additionally, U.S. Pat. No. 4,794,326 as well as U.S. Pat. Nos. 4,182,982 and 4,240,059 referenced therein further describe inductive detection technologies.
The prior art suffers from a number of deficiencies, including:
a. The prior art including the '917 device requires the target cable system under test to be made inoperable, the cable threaded through the signal detection device, and the cable system restarted in order to detect voltages, currents, and data signals on the cable. PA1 b. The prior art cannot adequately handle various types of conductive cables including coaxial and shielded or unshielded twisted pair cables. PA1 c. The prior art does not detect more than one networking communication signal frequency. PA1 d. The prior art does not have sufficient sensitivity for certain applications including detecting small signals on local area network LAN cables. PA1 e. The prior art lacks a cable alignment mechanism to ensure accurate signal detection.